The Schmidt–Rubin rifles were a series of Swiss
Army service rifles in use between 1889 and 1958.
They are distinguished by the straight-pull bolt action invented by Rudolf
Schmidt and use Eduard Rubin's 7.5×55mm Schmidt–Rubin rifle
cartridge.

The Karabiner Model 1931 (K31) is a magazine-fed, straight-pull
bolt action rifle. It was the standard issue rifle of the Swiss armed
forces
from 1933 until 1958 though examples remained in service into the 1970s.
It has a 6-round removable magazine, and is chambered for the 7.5×55mm
Swiss.

This is a 1945 dated example is in very good condition
including the bore.
Mathching Serial numbers & comes with an original K31 Leather Sling